Stitching machine



Nov. 22, 1960 w. E. HAUSKNECHT 2,960,695

STITCHING MACHINE 5 Sheets-Sheet 1 Filed Nov. 20, 1959 INVENTQR.

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STITCHING MACHINE Filed Nov. 2o, 1959 5 Sheets-Sheet 3 INVEN TOR: Will/'am E Haus/mec Nov. 22, 1960 w. E. HAusKNEcHT 2,960,695

STITCHING MACHINE Filed NOV. 20, 1959 5 Sheets-Sheet 4 INVENTOR:

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STITCHING MACHINE Filed Nov. 20, 1959 @2a e@ 38a 4050 6a-6 @1,22

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United States Patent O i srrrcnrNG MACHINE William E. Hauslrnecht, Palos Park, lll., assigner to Acme Steel Company, Chicago, Ill., a corporation of Illinois Filed Nov. 20, 1959, Ser. No. 854,379

12 Claims. (Cl. 1-2) This..invention Vrelates to` improvements in stitching n iachinesV for use in stitching together the cover flaps of fihreboard boxes, cartons, and Vthe like. andV is an improvement upon the type of stitching machine which is disclosed in the United States Letters Patent of George H. Reed, No. 2,635,234, dated April 21, 1953, and in his application Serial No. 294,352, led June 19, 1952, now Patent No. 2,861,269.. The present application is a continuation-in-part of co-pending application Serial No. 578,207, filed April 16, 11956, now abandoned.

The present improvement relates particularly to the form of stitching machine described and claimed .in the application of George H. Reed and William P. Porcelli, Serial No. 501,482, filed April 15, 1955, now Patent No. 2,839,753, which discloses a stitching machine comprising means for causing the legs of a metal staple to be curled and clinched within or beneath the overlapping cover flaps of a carton las the staple is being driven without the use of a clinching member or anvil beneath the flaps. In the machine of said last mentioned application means are provided for varying and controlling the curl of the staple legs as they are driven through the m-aterial being stitched, without the use of a clinching anvil, and thereby controlling the shape of the clinched staple.

The principal object of the present invention is to provide improved means for controlling the curl of the legs of the staple as they are driven through the material being stitched and thereby controlling the shape of the clinched staple. A further object of the invention is to provide a stitching machine having means for forming and driving a staple including means for curling the staple legs into or through the work as they are driven, wherein there is provided an adjustableshoe for supporting the staple legs and controlling their movements during the curling operation in order to obtain the desired curling effect. Other objects-relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment of the improved stapling machine is illustrated. In the drawings,

Figure 1 shows a partial front elevationof a staple forming and driving machine embodying the present invention with parts thereof removed and with other parts shown in vertical section;

Fig. 2 shows a sectional view taken on the line 2-2 of Fig. 1, illustrating the wire feeding mechanism;

Fig. 3 shows a rear elevation on the line 3--3 of Fig. 2 with parts broken away;

Fig. 4 shows a partial front elevation of the Wire feeding wheels shown in Figs. 1 and 2 in engagement with the stapling wire;

Fig. 5 shows an enlarged section taken on the line 5---5l of Fig. 4, illustrating the means for imparting a transverse curvatureV to the stapling wireduring the feeding operation;

2,960,695 Patented Nov. 22, 196() ICC Fig. 6 shows a perspective view of the preferred form of staple used in the practice of the present invention;

Fig. 7 shows a vertical section through the upper lefthand corner portion of the apparatus as illustrated in Fig. 1, illustrating the means for controlling the relative adjustment and separation of the Wire feed rolls; v

Fig. 8 shows a sectional view similar to the right-hand portion of Fig. 7, illustrating the position of the cam when the feed wheels are separated;

Fig. 9 shows a sectional view taken on the line 9-9 of Fig. 7;

Fig. 10 shows a vertical sectional view throughthe apparatus, taken on the line 10-10 of Fig.. l;

Fig. 11 shows a perspective view of the wire gripping and staple forming anvil embodied in the stapling apparatus illustrated in Figs. 1 and 10;

Fig. .12 shows an exploded perspective view of the parts of the anvil mechanism illustrated in Fig. l1;

Fig. 13 shows a bottom plan view of the wire cutting mechanism embodied in the stitching apparatus shown in Fig. l;

Fig. 14 shows a sectional View taken on the line 14.--14 of Fig. 13;

Fig. 15 shows a top plan View of a portion of the stapling, illustrating the method of dividing it into staple lengths by diagonal cuts;

Fig. 16 shows a front elevation of the wire gripping, staple forming and staple driving and clinching parts of the apparatus with portions thereof shown in verticalsection, illustrating the par-ts in the relative positions which they occupy prior to the formation of a staple, with the staple leg supporting shoe in its retracted position;

Fig. 17 shows a side elevation of the partsjillustrated in Fig. 16, looking toward the left as Viewed in Fig. 16;

Fig. 18 is a view similar to that o-f Fig. 16, showing the relative positions of the parts after a staple has been formed and is about to be driven into the work;

Fig. 18a is a sectional view taken on the line 18a- 18a of Fig. 19;

Fig. lSb is a sectional View similar to that of Fig. 18a but illustrating a modification;

Fig. 19 shows a side elevation of the parts illustrated in Fig. 18, looking toward the left as viewed in* Fig. 18, with the par-ts in the same relative positions;

Fig. 20 is a horizontal section taken on the line 2li-2li of Fig. l;

Fig. 21 is a view similar to those of Figs. 16 and 18, illustrating the relative positions of the parts after the staple vhas been almost completely driven and clinched;

Fig. 22 shows a side elevation of the parts in the relative positions they occupy in Fig. 21, looking toward the left as viewed in Fig. 21; l

Fig. 23 shows an enlarged vertical section through the lower portion of the staple driver, adjacent portions of the staple formers and the intervening parts of the stap-le supporting shoe, illustrating in detail the method of curling the legs of the staple `as it is being driven;

Fig. 24 shows a bottom plan view of a portion of `the lower one of two carton flaps which 4have been stitched together by driving a staple in the manner illustrated in Fig. 23, showing the staple legs clinched on the underside of the lower ap; and

Fig. 25 shows a vertical section taken on the line 25-25 of Fig. 24.

As illustrated in the drawings, the invention is embodied in a machine comprising a stitching head 27 adapted to be located above the carton flaps which are to be stitched together with the use of the stapling wire 28 which is drawn from a spool or the like by means of feeding mechanism Sti and fed through a guideway 31 and through a tubular shearing block 32 adjacent :which it is cut olif to4 form .a length ofwire 28a which is Yadapted to be formed into a-U-shaped staple 29 (Fig. 6) while it is being held by anvil mechanism indicated generally at 33 and shown particularly in Figs. ll and l2. After the staple is formed it is driven through the flaps of the carton and, as the staple is driven, the anvil mechanism is retracted and the staple legs are supported on their inner sides by a retractable shoe 34 which gradually recedes as the staple is driven into the work. As the staple is driven, the legs 29a are curled inwardly toward each other as hereinafter described, so that the staple finally assumes the form shown in Figs. 24 and 25.

The head 27 of the machine comprises a frame or housing 35 having a face plate 36 secured to the front side thereof by screws 37. The face plate 36 is provided on its inner side with a vertical guideway 36a in which a former bar 38 is mounted to reciprocate. The former bar is provided on its outer side with a longitudinal groove 38a of rectangular cross section which is slidably engaged by a driving bar 40. The former bar 38 has secured to the lower end thereof two spaced parallel formers 41 which are attached by screws 42 and which are reversible in their positions on the bar so that the stable engaging portions thereof may be renewed without replacing the formers entirely. The formers 41 are adapted to bend the projecting ends of the staple wire length 28a downwardly to form the staple legs 29a as the former bar 38 is moved downwardly and, during this movement, the staple legs occupy longitudinal grooves 41a in the opposed faces of the formers, as more fully described hereinafter.

The driving bar 40 has keyed to the lower end thereof a staple driver 43 which is reversible in its position on the driving bar and which is provided with slightly concaved end faces 43a, the lower one of which is adapted to engage the top wall 29b of the staple to effect the driving of the staple as the driving bar moves downwardly.

In order to actuate the former bar 38, it is provided between its ends with an aperture engaged by a threaded pin 44 which is held in place by a nut 45 and which is provided with a cylindrical extremity 44a having mounted thereon a roller 46 adapted to travel in a continuous irregular groove 47a formed in the side face of a cam 47. This cam has a hub portion 47h which is journaled in a bearing 35a formed in the housing 35. The hub portion is keyed to a shaft 48 which is also journaled in a bearing in the housing 35 and which is adapted to be driven at a uniform speed by an electric motor or the like. As the shaft is rotated, the cam 47 is driven at constant speed and the former bar 38 is actuated to cause the formation of a staple during each rotation of the cam. f

The rotation of the cam 47 also serves to effect the reciprocation of the driving bar 40 through connections comprising a transversely extending pin 40a formed on the upper end thereof which is journaled in a bushing 49 secured in the upper end of a crank arm 50. The lower end of this crank arm is provided with a transversely extending p-in 51 (Fig. 20) which is journaled in a sleeve 52a formed in the end of a link 52, the function of which is described hereinafter. This sleeve 52a is in turn journaled in a cylindrical recess 47C formed in the face of the cam 47 at a point displaced radially from the axis of the cam. Thus, when the cam is rotated, the pin 51 revolves about the axis of the cam and thereby causes the crank arm 50 to effect a reciprocation of the driving bar 40. The recess 47C in the cam is so located that the downward movement of the driving bar 40 will be effected in proper timed relation to the movement of the former bar 38 so that a staple will be formed and will be in readiness to be driven when the staple driver 43 carried by the driving bar 40 arrives at a position where it is about to engage the formed staple.

The wire feeding mechanism 30, shown particularly in Figs. l, 2, 3, 4, 5, 7, 8 and 9, is actuated by the previously mentioned link 52 which is actuated by the cam 47 through the sleeve 52a (Fig. 20). This link is pivotally connected at 54 to a lever 55 which has its lower end pivo-ted at 56 on a plate 57 mounted for pivotal movement on the casing 35. The reciprocation of the link 52 in response to the rotation of the cam 47 causes an angular oscillation of the lever 55 which actuates a pivotally connected curved link 58 having a connection by a pivot pin 59 to the upper end of the lever 60 (Fig. l), which actuates the wire feeding mechanism through an over running clutch of the type disclosed in the United States Letters Patent of Howard G. Allen, No. 1,513,021, dated October 28, 1924, whereby an intermittent feeding movement is imparted to the stitching wire 28.

The crank arm 60 is rotatably mounted upon a shaft 61 located in the housing 62 of the feed mechanism. This crank arm has a pin 63 projecting from the side thereof to engage a slot 64a formed in the side of the clutch driving ring 64 which is mounted to rotate about a clutch disk 65 fixed upon the reduced extremity 61a of the shaft. The disk 65 is provided with side plates 65a which are secured thereto and which overlap at their outer edges the inner margin of the ring 64, as shown in Fig. 3. The disk 65 and its plates 65a are held against movement endwise of the shaft by a cap member 67 which is secured to the end of the shaft. The disk 65 is provided with an annular series of spaced pockets 65b in each of which there is mounted a cylindrical roller 66. These pockets are provided with bottom walls 65C which are at right angles to radii of the disk and are so positioned that they converge with the surrounding annular surface 64b of the ring 64 toward one end of the pocket. Each roller 66 is thus adapted to wedge between a surface 65C and a surface 64b at is moves toward one end of its pocket but to be released as it moves toward the other end. A coil spring 68 is mounted in each pocket to press the contacting roller normally toward the small end of the pocket and when the ring 64 is rotated in a direction to urge the rollers 66 toward the small ends of the pockets, a driving connection is thereby established between the ring 64 and the disk 65 which is fixed upon the shaft 61. When the crank arm 60 is moved in the reverse direction, the ring 64 tends to move the rollers 66 toward the large ends of the pockets 65b so that the ring 64 then moves freely around the disk 65 and the shaft 61 remains stationary. In this way an intermittent rotary motion is imparted to the shaft 61 by the reciprocatory movement of the link 52.

This intermittent motion is made use of for effecting an intermittent feed of the stitching wire 28 which passes between two feed wheels 70 and 71 which feed the stitching wire 28 and also impart an arcuate cross section thereto. These feed wheels are fixed on the hubs of two gears 72 and 73, respectively, which mesh with each other and cause the feed wheels to be rotated in opposite directions. The gear 72 is secured upon the end of the shaft 61 and the other gear 73 is journaled upon a shaft 74 which is fixed on the depending portion 75a of an L-shaped lever 75 pivoted on a pin 76 fixed in the face plate 36. The long arm 75b of the bellcrank lever 75 has a threaded aperture 75a which is threadedly engaged at its upper end by a plug 77. A coil spring 78 has its upper end engaging the plug 77 and its lower end seated in a recess in the face plate 36 so that it tends normally to rock the lever 75 about its pivot 76 and thereby move the feed wheel 71 toward the feed wheel 70 to press against the stitching wire 28.

In order to separate the feed wheels 70 and 71 from each other, the lever arm 75b is provided at its free end with a projecting cam 79 of semicircular cross section having a flat face 79a. A shaft 80 is rotatably mounted in the face plate 36 adjacent to the lever arm 75b and a semicircular cam 81 is fixed on this shaft with its at face 81a disposed opposite to the face 79a of the cam 79. A crank arm S2 is fixed upon the shaft 80 and may be manipulated by the operator to rotate the cam 81 from the position shown in Fig. 9 to the position shown in Fig. 8 'and thereby separate the feed wheel 71 from the feed wheel 70.

The feed wheel 70 is provided around its periphery with an annular groove 70a which is engaged by an annular rib 71tz'formedon the periphery of the `feed wheel 71. The bottom wall 70bof the groove is transversely curved and the outer annular surface 71b of the rib 71a has a similar transverse curvature so that, as the stitching wire 28 passes between the feed rolls in the direction of the arrow 84, shown in Fig. 4, it is substantially confined between the surfaces '70b and 71b, with only a slight clearance, and it is also confined between the side walls 7 0c of the groove. The stitching wire is thus caused to conform to the curvature of the surfaces 70b and 71b and this curvature is such that the stitching wire is stressed beyond the elastic limit of the metal so that a permanent transverse curvature is thereby imparted to the stitching wire and it has this transversely curved form when it enters the guide 31.

The depth of the arc of the transverse curvature in the stitching wire 28 may be varied by adjusting the posi tion of the plug 77 in the lever arm 75b and thereby varying the compression of the spring 78 with a corresponding variation of the pressure with which the feed Wheel 71 presses the stitching wire. against the feed wheel 70.` By thus varying the depth of the arc of transverse curvature in the stitching wire it is possible to vary the extent to which the legs of the staple are curled by the devices hereinafter described.

For the purpose of cutting off the increment of stitching wire 28a which is projected through the anvil mechanisin 33, as shown in Fig. l, the machine is provided with a cutting blade 85 (Fig. 14) which is attached by a screw 86 to a projecting portion 37a of a bar 87 mounted to reciprocate in a casing 88 -on which the stitching wire shearing block 32 is formed. The casing 88 is attached to the face plate 36 and the bar 87 is mounted for vertical sliding movement therein, being held normally in itsfupper position by a coil spring 89 which is mounted inY a tubular bore formed in the bar with its lower end resting on the casing immediately above the stitching wire guide 32. Y

vThe cutting blade 85 is provided at ifs lower end .with a Vshaped cutting edge, as shown in Fig. 14, and it moves in a vertical plane which is at an angle to the longitudinal axis of the stapling wire 28 which moves through the shearing block 32 so that when the blade 8.5` descends, it cooperates with the stationary shearing die formed by the edge of the block to sever the wire along a diagonal line 28h, shown in Fig. 15. The result is that the resulting staple 29 formed from a length 28a of stapling wire has legs 29a (Pig. 6) which are pointed at their edges, as shown at 29C, the point for each leg being on the edge Opposite to that on the other leg. r1`his facilitates the driving of the staple and the desired curling action of the legs during the driving operation.

At the proper time in the cycle of operations, the bar 87 is moved downwardly to sever the stitching wire and this is effected vby an adjustable pin 90 mounted on an arm '91 which is fixed on a shaft 92 journaled in the face plate 36 and arranged to extend into the interior of theV housing 35. Within this housing a curved operating arm 93 is secured on the shaft 92 with its tip located in a position to be engaged by a projection 50a on the lower end of the link S0. Thus, once during each cycle, the projection 50a rocks the arm 93 in a counter- Iclockwise direction, as viewed in Fig. 1, thereby causing'the pin 90 -to move the bar 87 downwardly against the compression of the spring S9 with the result that the blade 35 cuts olf a length of stitching wire 28a. After this length is cut oif, the former bar 33 is moved downwardly by the cam 47 with the result that the wire is formed into a staple having the shape shownin Fig. 6, after which the driving bar causes the driver 43 to project the staple through the work.

For the purposev of adjusting the length of the increment of the stitching wire 28 which is'fed by the wire feeding mechanism 30 upon each rotation of the cam shaft 48, a handle is provided to turn the plate 57 about its pivot 96 and thus vary the position of the pivot S6 of the lever 55, thereby varying the amplitude of movement of the crank arm 60 upon each reciprocation of the link 52.` Also, the plate 57 is provided with an arcuate slot 57a engaged by a roller 97 mounted on a bar 98 attached tothe casing 88. This casing is slidab-ly mounted on the face plate 36 so that, if the plate 57 is adjusted by the handle 95 to increase the length of the increment 28a of stitching wire which is fed through the anvil mechanism 33 upon each rotation of the cam 47, the casing 80 will at the same time be adjusted to vary the spaced relation of the cutting blade 8S and the shearing block 32 with respect to the anvil mechanism 34 so that both legs of the staple to be formed will be of substantially the same length. 'Ihese features of adjusting the length of the cut-off sections cf staple wire and causing the legs of the staple to be c-f equal length do not in themselves constitute parts of the present invention.

rlhe anvil mechanism 33 which holds the cut-olf section of wire 28a when itis severed by the shearing device is shown particularly in Figs. l, 10, l1, 12, 16, 17, 18 and 19 and comprises the anvil die 100 which is mounted on the lower end of the anvil carrier 101. This anvil carrier is pivotally mounted by a pin 102 in a chamber 103:1 formed in the lower end of a cover block 103 which is secured by screws 104 to the face plate 36. The anvil and the lower part of the carrier 101 are normally caused to swing toward the path of movement of the driving bar 40 by the action of a leaf spring 105 which has its lower end 10501 en gaging a recess 101a in the anvil carrier. The side walls 101b of the recess 10M are bent inwardly to interlock with the curved portion 105e of the spring which is adjacent to `its lower extremity 105i). The upper end of the spring 105 extends into a recess 103b formed in the upper inner side of the block 103 where it coacts with the lower side face of the face plate 36, so that the spring operates normally to swing the lower end of the carrier 101 with its anvil 100 to a position where a V-shaped projection 101C, formed on the anvil carrier, lies in the path of movement of the staple driver 43, as shown, for example, in Fig. 17.

The anvil 100 has a part 100er over which the cut-off length of stitching wire 28a is adapted to be bent to form a staple of the form shown in Fig. 6. This part may be of various widths but it is shown as being rather wide so that the resulting staple will embrace a substantial portion of the cart )n aps when it is driven and clinched as shown in Fig. 25. The part 10011 is carried by a small block 100]) which is pivotally mounted by a pin 107 between the flanges 101e on the lower end of the anvil carrier. The part 100b of the anvil has a tail portion which extends upwardly and rearwardly from the top of the part 100e: and this tail portion has an inclined surface 100C which is adapted to engage an inclined surface 10M formed on the anvil carrier between the flanges 101e, -thereby limiting the downward movement of the die portion 100a during the formation of the staple. A coil spring 108 is mounted in a recess formed in the part 10015 of the anvil and in the lower part of the anvil carrier and this spring tends normally to move the anvil die 100a t0 theposition shown in Fig. 17, Where the pressure of Ithe spring 108 is adapted to cause the anvil to Vgrip the section 23a between its top face and the lower face ofthe projection 101e formed on the anvil carrier. One side of the projection 101C is provided with a V-shaped notch or guideway 101g which is adapted to .engage the :end of the wire 28 as it is being fed by the wire feeding. mechanism 30 in order to direct the wire into proper position to be gripped and to cause the gripping to take place automatically as the gripping parts are separated against the compression of the spring 108 -by the moving wire. The gripping of the wire 28a by the spring actuated anvil 100 continues until the anvil is moved downwardly during the staple forming operation to the position shown in Fig. 19.

After the wire has been positioned in the anvil mechanism in the manner illustrated in Figs. 1, 16 and 17, and after the section 28a has been cut off by the downward movement of the cutting blade 85, the cam 47 actu` ates the former bar 38 to cause the dies 41 to move downwardly and to engage and bend downwardly the projecting ends of the cut-off piece 28a. These end portions of this piece o-f wire pass into the longitudinal grooves 41a in the dies and, as the former bar 38 moves downwardly, they are bent downwardly to form a U- shaped staple as shown in Figs. 18 and 19. As this downward movement proceeds, the anvil 100 is adapted to tilt about its pivot 107 until the surface 100e` engages the surface 101], thus causing the anvil to be firmly supported during the formation of the staple. The staple is then free to move out of engagement with the anvil.

The present invention is directed particularly to the combination with the features described above of the previously mentioned supporting shoe 34 which is carried by the curved arm 110 pivoted at 111 in an aperture in the former bar. The shoe 34 is arranged to extend between the staple legs when the staple is formed, as shown in Figs. 18 and 19, and it comprises three complementary parts 34a, 34h and 34e arranged side by side in parallel relationship. These parts are similar in shape, having pointed extremities 34d adapted to enter the space between the staple legs and having curved top surfaces adapted to be engaged by the driver 43 when the driver moves downwardly and cams the member 34 out of its position between the staple legs during the process of driving the staple. The parts of the shoe are connected to each other and to the arm 110 at their upper ends but the body portions thereof are spaced apart and are normally separated from each other due to their own resiliency. They may be drawn together by screws 112 which pass through apertures in the parts 34a and 34b and threadedly engage apertures in the part 34C so that the spaced relation of the parts and the pressure with which the outer parts 34a and 34a bear upon the inner sides of the staple legs may be varied through a substantial range. This adjustability of the shoe 34 is important in connection with the control of the curling of the staple legs, as hereinafter more fully described.

The shoe 34 is moved toward the staple leg supporting position shown in Fig. 18 by a roller 114 mounted on the end of a plunger 115 (Fig. 10) which is mounted to slide in a cylinder 116 attached to the housing 35. A coil spring 117 actuates the plunger to move the shoe 34 to the supporting position and the extent of that movement is limited by a rod 118 attached to the plunger which carries a disk adapted to engage a stop (not shown) to arrest the plunger. The shoe 34 is maintained in contact with the roller 114 by a coil spring 119 which has its ends mounted in sockets formed in the former bar 38 and in the arm 110. The shoe is retracted against the compression of the spring 117 during the staple driving operation by the engagement of the beveled ends of the driver 43 and the driving bar 40 with the inclined wedging surface 34e on the shoe members.

Referring now to the driving of the staple 29after it has been formed in the position shown in Figs. 18 and 19, the rst operation is the retraction of the anvil 100 by the descending driving member 43 which engages the inclined top face of the projection 101e. The driving member 43 then engages the top wall of the staple and forces it downwardly between the formers 41 and into the work with the ribs 43b on the sides of the driver traveling in the guide channels 41a of the formers.l As

this operation proceeds, the staple legs 29a travel in the guide channels 41a which have their back walls bowed outwardly toward their lower ends as shown at 41b. The lower ends of these curved portions turn inwardly toward each other, as shown in Fig. 23, and terminate in extremities 41c where the back wall of the groove is in vertical alignment with the back wall 41d of the straight portion of the groove 41a in the intermediate part of the former. As the staple legs 29a move downwardly, they are directed into the outwardly bulged portions 41b of the guide channels by the outwardly bulging lower side portions 34j of the shoe segments 34a and 34C. Thus, the staple legs are deflected first outwardly and then inwardly toward each other as they travel through the formers with the result that they curl in- Wardy toward each other. As this action continues, the parts of the shoe 34 are cammed out of the path of travel of the driving member 43 and the staple is completely driven and curled so that it takes the form shown in Figs. 24 and 25 where the flaps 120 of the carton are securely stitched together.

The curling action of the former dies and the shoe on the staple legs may be varied by adjusting the shoe 34 to vary the pressure of the projections 34a on the legs and the curling action may be further regulated by varying the depth of the crown of the stapling wire. It is desirable to employ stapling wire which is transversely curved since this form of wire has been found to have greater penetrating ability than flat wire and has greater column strength so that it is unlikely to bend or buckle except in response to the action of the projections 34j of the shoe and the portions 41a and 41e of the formers. The depth of the arc or crown of the stitching wire may be varied by adjusting the position of the threaded plug 77 in the arm 75b of the feeding mechanism 30. This varies the pressure of the feed wheels 70 and 71 on the stitching wire 28 so that the arc of the crown may be regulated in conjunction with the adjustment of the shoe 34 to obtain the best results. When the depth of the arc of the stitching wire is increased by adjustment of the pressure of the feed wheels 70 and 71, there is an increase in the compression of the legs of the staple between the parts 34f and 41e with a resulting increase of the curvature imparted to the staple leg as it is being driven. Similarly, where there is a decrease in the depth of the arc of the staple leg by varyingv the pressure of the feed wheels 70 and 71, there is a decrease in the pressure of the parts 34j and 41e on the staple leg with a corresponding decrease in the curvature imparted to the staple leg while it is being driven. Similar variations in curvature of the staple leg may be brought about by adjustment of the stud 112 to vary the spaced relation of the parts 34a and 34C of the shoe. It is believed to be important to have the tips 41d of the formers terminate substantially in line with the back walls of the straight portions of the former grooves 41a so that the top walls 29b of the staples will not be compressed or buckled as they pass the lower ends of the formers?. This precaution insures the driving of complete staples Without any deformation thereof other than the desired curling of the legs.

A modified form of the shoe 34 is illustrated in Figure 18b and for identification is designated with the numeral 34. Functionally, the shoe 34 is substantially identical to the shoe 34 and structurally is quite similar and comprises three complementary elements 34a', 34h and 34e arranged in side-by-side parallel relation. These components are similar in shape and have pointed extremities 34d adapted to enter the space between the staple legs and have curved top surfaces adapted to be engaged by the driver 43 when the driver moves downwardly so as to cam the shoe laterally into a position remote from the staple legs so that the staple can be driven completely into the work material.

Essentially, the shoe 34 difers from the shoe 34 in the manner in which it is adjusted to effect a change in the width thereof and thereby alter the curl imparted to the legs of the staple. More particularly, the elements 34a' and 34e' are respectively provided with threaded openings extending therethrough, and mounted in these openings are screws 112a and 112b. The screws 112a and 112b respectively engage the center component 34b of the shoe and as the screws are turned in one direction to move the same farther into the threaded openings associated therewith, the elements 34a and 34e' will be exed laterally outwardly from the element 34b with the result that the width of the shoe 34 will be increased. Conversely, rotating the screws in the opposite direction will tend to withdraw the same from the center element 34b with the result that the elements 34a and 34C will be displaced laterally inwardly toward the normal position thereof.

It is evident that the shoe 34 has initially a minimum dimension enforced thereon by the resiliency of the three interconnected elements 34a', 34b and 34e', and that the screws 112a and 11219 are effective to adjustably increase the width of the shoe, while the shoe 34, as shown best in Fig. 18a, has initially a maximum dimension and that the screws 112 are effective to adjustably decrease the width of the shoe 34. This construction of the shoe 34 permits individual adjustment of the elements 34a' and 34e', in contradistinction to the shoe 34 wherein the elements 34a and 34e are simultaneously adjusted, which affords more precise adjustment of the shoe and tailoring of the width thereof to more accurately control and determine the bending of the staple legs as shown in Fig. 23. Further, such individual adjustment of these elements permits ready accommodation of dimensional discrepancies arising from manufacturing tolerances as well as wearing of the outer edges of the elements 34a' and 34e' and wearing of the respectively corresponding edges of the formers 41.

Although various forms of the invention have been shown and described by way of illustration, it will be understood that the invention may be constructed in various other embodiments which come within the scope of the appended claims.

I claim:

l. The combination in a wire stitching machine, of means for driving a wire staple into the work, guiding means for engaging the outer sides of the staple legs as they are driven, means for supporting the inner sides of the staple legs as they are driven, said guiding and supporting means having opposing parts formed to impart a curl to said staple legs during the driving operation, and means for adjusting said supporting means to vary the curl of said legs.

2. The combination in a wire stitching machine, of means for driving a wire staple into the work, staple formers for guiding the outer sides of the staple legs as the staple is driven, a shoe mounted to support the inner sides of the staple legs and having parts formed to cooperate with said formers to cause the legs of said staple to curl as the staple is driven, and means for adjusting the effective width of said shoe to vary the curl imparted to said legs.

3. The combination in a wire stitching machine, of means for driving a wire staple into the work, staple formers for guiding the outer sides of the staple legs as the staple is driven, a retractable shoe adapted to support the inner sides of said staple legs and to be retracted by the driving of the staple, said formers having parts shaped to cooperate with said shoe to cause the longitudinal curling of said staple legs, and means for adjusting the effective Width of said shoe to vary the curl imparted to said legs.

4. The combination in a wire stitching machine, of means including staple formers for bending a length of Stitching wire into the form of a staple, said staple 10 formers having means for guiding the staple legs, means for driving said staple through said formers into the work, means including parts of said formers and a shoe located between said staple iegs to cause said staple legs to curl as they are driven, and means for adjusting the eifective width of said shoe to vary the curl of said legs.

5. The combination in a wire stitching machine, of means including staple formers for bending a length of stitching wire into the form of a staple, said staple formers having means for guiding the staple legs, means for driving said staple through said formers into the work, said guiding means being bowed outwardly adjacent its lower end, a retractable shoe positioned between said staple legs and having outwardly projecting side portions adapted to cooperate with said outwardly bowed portions of said guidlng means to cause the legs of said staple to curl inwardly toward each other as they are driven, and means for adjusting the spaced relation between said projecting side portions and said outwardly bowed portions to vary the curl imparted to said legs.

6. The combination in a wire stitching machine, of means for driving a wire staple into the work, means adapted to engage the outer sides of the staple legs in advance of the work, means adapted to engage the inner sides of the staple legs in advance of the work, said two last named means being formed to cause said legs to curl as they are driven, and means for adjusting said means which engages the inner sides of said staple legs for regulating the degree of curl of said legs.

7. In a wire stitching machine wherein stitching wire has a transverse curvature imparted thereto prior to being cut into predetermined lengths, the combination of staple formers for bending such lengths into leg-equipped staples, means for driving such staples into a work material, means for engaging the outer sides of sail staple legs in advance of the work material, means for engaging the inner sides of the staple legs also in advance of the work material, said two last named means being formed to cause said legs to curl longitudinally as they are driven, and means for adjusting one of said two last named means for varying the degree of curl imparted to said legs.

8. In a wire stitching machine wherein stitching Wireis severed into predetermined lengths preparatory to forming leg-equipped staples therefrom, the combination of means for imparting a transverse curvature to such stitching wire in advance of the severance thereof into such predetermined lengths, means for bending the severed lengths into such leg-equipped staples, means for driving such staples into a work material, means for causing the legs of such staples to curl longitudinally as they are driven, and means for varying the degree of curl imparted to the legs of such staples.

9. The combination of claim 8 in which means are provided for varying the arc of the transverse curvature imparted to such stitching wire.

10. The combination in a wire stitching machine, of means for driving a wire staple into a work material, staple formers for guiding the outer sides of the staple legs as the staple is driven, a shoe mounted to support the inner sides of the staple legs and having a pair of elements formed to cooperate with said formers to cause the legs of said staple to curl as the staple is driven, said elements being relatively movable in lateral directions for adjusting the effective Width of said shoe to vary the curl imparted to such staple legs, and means for adjusting said elements to determine the width of said shoe.

ll. The combination of claim 10 in which said means is in engagement with each of said elements and effects simultaneous adjustment thereof.

12. The combination of claim l0 in which said means comprises a pair of adjusting members respectively engaging said elements for selectively adjusting the same.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. testes C November 22, 1%@

William E. Hausknecht It is herebycertified that error appears n the `above nimbered Aplattent requiring correction and that the said Letters Patent should read as corrected below.

signed and sealer; this 2nd day of AMay 1961.

- SEAL) Attest:

ERNES1 W. SWDER r Y DAVTD L. LADD Attesting Officer Commissioner of Patents 

